Re: *Zeros

Scott (and Jerry)

Another example of this kind of thing is if you try the following 2 lines of
code (assuming String is a 10-byte character variable):

String = *all'A';
String = 'B' + *all'A';


The first line is fine and would fill the String variable with 'AAAAAAAAAA'.
However, the program won't compile if you include the second line - in this
case, you'll get RNF7421 and RNF7416 errors (non-compatible operands). You'd
think that it should give you 'BAAAAAAAAA'....

Pesky intermediate operands :-)

Rory (http://www.linkedin.com/in/roryhewitt)


On 1/22/07, Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx> wrote:

Hi Jerry,

> So I'm thinking (always dangerous), "Oh, *Zeros is a character field."
> But, then, I remembered another line in this same program (and similar
> lines in tons of other programs:
> w#ladj = *Zeros;

Hmmm...When I think of *Zeros, I don't think of it as being the same thing
as the number 0.

You see, *Zeros is neither character nor numeric.  *Zeros is a special
value that tells the computer to fill the entire field (no matter what the
data type) to zeroes. The compiler may generate different code,
depending on the data type.

What sort of code would it generate when it's only one of many operands in
an expression?  That's where it gets murky.  There's no field to set to
all zeroes, is there? It's an expression, not a simple assignment where
there's a particular field to set.

You have this:

   w#ladj = *Zeros - dlsqty * dlstks;

I know it means "fill the whole field with zeroes" but there isn't really
a field for it to fill!  I suppose it might fill the intermediate result
with zeroes before moving on to the next step...  But, I don't find it
intuitive.

Anyway...  I don't have a solution (other than using 0 in place of
*Zeroes, which you've already done) but I thought you might find this
perspective interesting.

--
Scott Klement http://www.scottklement.com